Sound processor module

ABSTRACT

A behind-the-ear sound processor module includes a BTE-housing; an adjustable microphone module attached to the BTE-housing for capturing input audio signals from ambient sound; and a sound processor unit for generating, from the input audio signals, a neural hearing stimulation signal to be supplied to an implantable neural stimulation arrangement, wherein the microphone module comprises a plurality of microphones and a support element for carrying the microphones, wherein the support element is movable between a beamformer position enabling the plurality of microphones to act as a directional microphone array in a beamformer audio signal processing mode of the sound processor unit and a T-Mic position enabling at least one of the microphones to act as a T-Mic in a T-Mic audio signal processing mode of the sound processor unit at a position closer to the entrance of the ear canal than in the beamformer position.

The invention relates to a behind-the-ear (BTE) sound processor modulefor use in a device for neural stimulation of a patient's hearing, suchas a cochlear implant (CI) device.

The sense of hearing in human beings involves the use of hair cells inthe cochlea that convert or transduce acoustic signals into auditorynerve impulses. Hearing loss, which may be due to many different causes,is generally of two types: conductive and sensorineural. Conductivehearing loss occurs when the normal mechanical pathways for sound toreach the hair cells in the cochlea are impeded. These sound pathwaysmay be impeded, for example, by damage to the auditory ossicles.

Conductive hearing loss may often be overcome through the use ofconventional hearing aids that amplify sound so that acoustic signalscan reach the hair cells within the cochlea. Some types of conductivehearing loss may also be treated by surgical procedures.

Sensorineural hearing loss, on the other hand, is caused by the absenceor destruction of the hair cells in the cochlea which are needed totransduce acoustic signals into auditory nerve impulses. People whosuffer from sensorineural hearing loss may be unable to derivesignificant benefit from conventional hearing aid systems, no matter howloud the acoustic stimulus is. This is because the mechanism fortransducing sound energy into auditory nerve impulses has been damaged.Thus, in the absence of properly functioning hair cells, auditory nerveimpulses cannot be generated directly from sounds.

To overcome sensorineural hearing loss, numerous auditory prosthesissystems (e.g. CI systems) have been developed. Auditory prosthesissystems bypass the hair cells in the cochlea by presenting electricalstimulation directly to the auditory nerve fibers. Direct stimulation ofthe auditory nerve fibers leads to the perception of sound in the brainand at least partial restoration of hearing function.

To facilitate direct stimulation of the auditory nerve fibers, a leadhaving an array of electrodes disposed thereon may be implanted into thepatient's cochlea. The electrodes form a number of stimulation channelsthrough which electrical stimulation pulses may be applied directly toauditory nerves within the cochlea. An audio signal may then bepresented to the patient by translating the audio signal into a numberof electrical stimulation pulses and applying the stimulation pulsesdirectly to the auditory nerve within the cochlea via one or more of theelectrodes.

Typically, the audio signal, usually captured by a microphone, isdivided into a plurality of analysis channels, each containing afrequency domain signal representative of a distinct frequency portionof the audio signal, wherein the frequency domain signal in eachanalysis channel may undergo signal processing, such as by applyingchannel-specific gain to the signals. The processed frequency domainsignals are used for generating certain stimulation parameters accordingto which the stimulation signals for each stimulation channel aregenerated. The analysis channels are linked to the stimulation channelsvia channel mapping. The number of stimulation channels may correspondto the number of analysis channels, or there may be more stimulationchannels than analysis channels, or there may be more analysis channelsthan stimulation channels. Various stimulation strategies are used, suchas current steering stimulation (in order to stimulate a stimulationsite located in between areas associated with two or more electrodes)and n-of-m stimulation (wherein stimulation current is only applied to nof m total stimulation channels during a particular stimulation frame).

An example for such a CI system with electrical cochlea stimulation isdescribed in WO 2011/032021 A1.

Acoustic beamforming relates to methods of providing a plurality oftypically omnidirectional microphones with a directional/polar patternby applying appropriate signal processing to the audio signals capturedby the microphones, wherein the mutual distance of the microphones isutilized. Typically, hearing aids and auditory prostheses are providedwith such beamforming capability in order to enhance the signal-to-noiseratio of the desired audio signals.

US 2007/0016267 A1 relates to a CI device comprising a plurality ofmicrophones disposed on the BTE sound processor housing, the headpiecehousing and/or the cable connecting the sound processor and theheadpiece, in order to realize an acoustic beamformer arrangement.

Most CI systems have a built-in microphone located on the housing of theBTE sound processor, or on the headpiece that communicates with theimplanted part. However, since the positioning of the headpiece usuallyis optimized with regard to the transcutaneous signal transmission tothe implanted part of the system, the position of the microphone is notnormally optimal for picking up sound waves. Therefore, it is popular touse in addition an external microphone which is placed within the conchaof the ear near the entrance of the ear canal; such location is idealbecause it corresponds to the location where sound is naturallycollected by the concha. Such a type of external microphone is commonlyknown as a “T-Mic” microphone, where “T-Mic” is a registered trademarkof Advanced Bionics, AG. Typically, the T-Mic is held in its desiredposition by a boom or stalk which is attached to the ear hook of the BTEsound processor. An example of such a CI comprising a T-Mic is describedin WO 2011/059924 A1.

WO 2008/010716 A2 relates to a hearing aid comprising a BTE module andan in-the-ear (ITE) part connected to the BTE module, wherein the ITEpart is provided with a microphone and a loudspeaker and wherein the BTEmodule may comprise one or more microphones. Similarly, U.S. Pat. No.8,526,653 B2 relates to a BTE hearing aid comprising a loudspeaker to beplaced in the ear canal and a microphone to be placed at the entrance ofthe ear canal.

The use of a T-Mic is beneficial in many listening situations, since itutilizes the external ear's anatomy to achieve some shielding of soundsfrom the rear and the enhancement of important speech frequencies;further, it allows natural—and thus convenient—use of telephone devices.

However, in other listening situations, in particular for one-to-onelistening in noisy environments, the use of a tight beamformerarrangement could also be of great benefit. However, the size andorientation of today's cochlear implant sound processors limits theseparation available for microphones and hence their physical ability toproduce a beamformer.

It is an object of the invention to provide for a BTE sound processormodule enabling optimized picking-up of sound in different listeningsituations.

According to the invention, this object is achieved by a sound processormodule as defined in claim 1.

The invention is beneficial in that, by providing the BTE soundprocessor module with an adjustable microphone module which is movablebetween a beamformer position, enabling a plurality of microphones toact as a directional microphone array, and a T-Mic position enabling atleast one of the microphone to act as a T-Mic in a position closer tothe entrance of the ear channel than in the beam former position, thesound pick-up process can be optimized for the respective listeningsituation: the beamformer position of the microphone module may be usedin situations in which beamforming is particularly beneficial, and theT-Mic position may be used in situations in which the use of a T-Mic isparticularly beneficial.

Further, such microphone position-driven switching of the sound pick-upmode is particularly easy also for users with limited dexterity orvision, since it only requires handling of a—typically relatively largemicrophone module—rather than operation of e.g. small switches orbuttons.

Moreover, by providing an adjustable microphone module, the limitationsof the sound processor housing with regard to the placement ofmicrophones suitable forming a beamforming array can be overcome, sincethe microphone module allows a placement of the microphones without theusual constraints resulting from size, geometry and placement of thesound processor housing. Thus a beamformer with enhanced performance maybe realized.

Also, moving the microphones outside the sound processor module housingprovides for additional benefits: for example, the microphone module maybe replaced in case of damage or degradation, without the need toreplace the entire sound processor module; further, system flexibilitycan be enhanced, since the microphone module may be provided as aperformance upgrade of a more simple basic sound processor module,including simplification of the management of stock (typically, themicrophones are likely to be a weak point of the sound processormodule).

Preferred embodiments of the invention are defined in the dependentclaims.

Hereinafter, examples of the invention will be illustrated by referenceto the attached drawings, wherein:

FIG. 1 is a schematic representation of an example of a CI systemaccording to the invention;

FIG. 2 is a block diagram of an example of the signal processingstructure of a CI system according to the invention;

FIG. 3 is a schematic side view of an example of a sound processormodule according to the invention when placed at the ear of a patient,with the microphone module being shown in a beamformer position; and

FIG. 4 is a view like FIG. 3, with the microphone module being shown ina T-Mic position.

In FIG. 1 an example of a cochlear implant system is shownschematically. The system comprises a sound processing sub-system 10 anda stimulation sub-system 12. The sound processing sub-system 10 servesto detect or sense an audio signal and divide the audio signal into aplurality of analysis channels each containing a frequency domain signal(or simply “signal”) representative of a distinct frequency portion ofthe captured audio. A signal level value is determined for each analysischannel by analyzing the respective frequency domain signal. Stimulationparameters are generated based on the frequency domain signal and aretransmitted to the stimulation sub-system 12.

Stimulation sub-system 12 serves to generate and apply electricalstimulation (also referred to herein as “stimulation current” and/or“stimulation pulses”) to stimulation sites at the auditory nerve withinthe cochlea of a patient in accordance with the stimulation parametersreceived from the sound processing sub-system 10. Electrical stimulationis provided to the patient via a CI stimulation assembly 18 comprising aplurality of stimulation channels, wherein various known stimulationstrategies, such as current steering stimulation or N-of-M stimulation,may be utilized.

The stimulation parameters may control various parameters of theelectrical stimulation applied to a stimulation site including, but notlimited to, frequency, pulse width, amplitude, waveform (e.g., square orsinusoidal), electrode polarity (i.e., anode-cathode assignment),location (i.e., which electrode pair or electrode group receives thestimulation current), duty cycle, spectral tilt, ramp on time, and rampoff time of the stimulation current that is applied to the stimulationsite.

Sound processing subsystem 10 and stimulation subsystem 12 may beconfigured to operate in accordance with one or more control parameters.These control parameters may be configured to specify one or morestimulation parameters, operating parameters, and/or any other parameteras may serve a particular application. Exemplary control parametersinclude, but are not limited to, most comfortable current levels (“Mlevels”), threshold current levels (“T levels”), dynamic rangeparameters, channel acoustic gain parameters, front- and back-enddynamic range parameters, current steering parameters, amplitude values,pulse rate values, pulse width values, polarity values, filtercharacteristics, and/or any other control parameter as may serve aparticular application.

In the example shown in FIG. 1, the stimulation sub-system 12 comprisesan ICS 14, a lead 16 and the stimulation assembly 18 disposed on thelead 16. The stimulation assembly 18 comprises a plurality of“stimulation contacts” 19 for electrical stimulation of the auditorynerve. The stimulation assembly 18 may be inserted within a duct of thecochlea in such a manner that the stimulation contacts 19 are incommunication with one or more stimulation sites within the cochlea,i.e. the stimulation contacts 19 are adjacent to, in the generalvicinity of, in close proximity to, directly next to, or directly on therespective stimulation site.

In the example shown in FIG. 1, the sound processing sub-system 10comprises a microphone module 70 including a plurality of microphones20A, 20B, 20C for capturing audio signals from ambient sound, a soundprocessor unit 24 which receives audio signals from the microphones 20A,20B, 20C, and a headpiece 26 having a coil 28 disposed therein. Thesound processor unit 24 is configured to process the captured audiosignals in accordance with a selected sound processing strategy togenerate appropriate stimulation parameters for controlling the ICS 14and may include, or be implemented within, a behind-the-ear (BTE) unitor a portable speech processor (“PSP”). In the example of FIG. 1 thesound processor unit 24 is configured to transcutaneously transmit data(in particular data representative of one or more stimulationparameters) to the ICS 14 via a wireless transcutaneous communicationlink 30. The headpiece 26 may be affixed to the patient's head andpositioned such that the coil 28 is communicatively coupled to thecorresponding coil (not shown) included within the ICS 14 in order toestablish the link 30. The link 30 may include a bidirectionalcommunication link and/or one or more dedicated unidirectionalcommunication links. According to an alternative embodiment, the soundprocessor unit 24 may be implanted and directly connected by wires withthe ICS 14, with the microphone module 70 remaining outside; in thiscase, an implantable microphone may be provided in addition to themicrophone module 70.

The sound processor unit 24 and the microphone module 70 together formpart of a sound processor module 25 to be worn behind the ear, as willbe explained hereinafter in more detail by reference to FIGS. 3 and 4.

In FIG. 2 a schematic example of a sound processor unit 24 is shown. Theaudio signals captured by the microphone module 70 are amplified in anaudio front end circuitry 32, with the amplified audio signal beingconverted to a digital signal by an analog-to-digital converter 34. Theresulting digital signal is then subjected to automatic gain controlusing a suitable automatic gain control (AGC) unit 36.

After appropriate automatic gain control, the digital signal issubjected to a filterbank 38 comprising a plurality of filters F1 . . .Fm (for example, band-pass filters) which are configured to divide thedigital signal into m analysis channels 40, each containing a signalrepresentative of a distinct frequency portion of the audio signalsensed by the microphone module 70. For example, such frequencyfiltering may be implemented by applying a Discrete Fourier Transform tothe audio signal and then arranging the resulting frequency bins intothe analysis channels 40.

The signals within each analysis channel 40 are input into an envelopedetector 42 in order to determine the amount of energy contained withineach of the signals within the analysis channels 40 The output signalsof the envelope detectors 42 are supplied to a mapping module 46 whichserves to map the signals in the analysis channels 40 to the stimulationchannels S1 . . . Sn. For example, signal levels may be mapped toamplitude values used to define the electrical stimulation pulses thatare applied to the patient by the ICS 14 via M stimulation channels 52.For example, each of the m stimulation channels 52 may be associated toone of the stimulation contacts 19 (FIG. 1) or to a group of thestimulation contacts 19.

The sound processor unit 24 further comprises a stimulation strategymodule 48 which serves to generate one or more stimulation parametersbased on the signals in the analysis channels 40 and in accordance witha certain stimulation strategy (which may be selected from a pluralityof stimulation strategies). For example, stimulation strategy module 48may generate stimulation parameters which direct the ICS 14 to generateand concurrently apply weighted stimulation currents via a plurality 52of the stimulation channels S1 . . . Sn in order to effectuate a currentsteering stimulation strategy. Additionally, or alternatively, thestimulation strategy module 48 may be configured to generate stimulationparameters which direct the ICS 14 to apply electrical stimulation viaonly a subset N of the stimulation channels 52 in order to effectuate anN-of-M stimulation strategy.

The sound processor unit 24 also comprises a multiplexer 50 which servesto serialize the stimulation parameters generated by the stimulationstrategy module 48 so that they can be transmitted to the ICS 14 via thecommunication link 30, i.e. via the coil 28.

The sound processor unit 24 may operate in accordance with at least onecontrol parameter, such as the most comfortable listening current levels(MCL), also referred to as “M levels”, threshold current levels (alsoreferred to as “T levels”), dynamic range parameters, channel acousticgain parameters, front- and back-end dynamic range parameters, currentsteering parameters, amplitude values, pulse rate values, pulse widthvalues, polarity values and/or filter characteristics. Examples of suchauditory prostheses, as described so far, can be found, for example, inWO 2011/032021 A1.

A schematic example of a BTE sound processor module 25 when worn at anear 11 of a patient is shown in FIGS. 3 and 4. The sound processormodule 25 comprises a BTE housing 27 to be worn behind the ear 11 and amicrophone module 70 attached to the BTE housing 27, for example via anadaptor 74. The use of such adaptor 74 allows to retrofit/upgradeproducts wherein the sound processor module did not include suchadjustable microphone module 70. The microphone module 70 comprises aplurality of microphones 20A to 20E which may be arranged, for example,as a linear array. The microphone assembly 70 preferably is designed asan ear hook.

The microphone module 70 comprises a support element 72 for carrying themicrophones 20A to 20E, which is preferably designed as an arm havingone free end 76 and one end connected to a joint 78 fixed at an upperend 29 of the BTE housing 27 (in the example of FIGS. 3 and 4, the joint78 is fixed at the upper end 29 via the adaptor 74).

The support element 72 is movable between a beamformer position enablingthe microphones 20A to 20E to act as a directional microphone array in abeamformer audio signal processing mode of the sound processor unit 24and a T-Mic position enabling at least one of the microphones 20A to 20Eto act as a T-Mic in a T-Mic audio signal processing mode of the soundprocessor unit 24, with the at least one microphone acting as the T-Micbeing located in the T-Mic position of the microphone module 70 in aposition closer to the entrance 13 to the ear canal than in thebeamformer position of the microphone module 70. In the example of FIGS.3 and 4, the support element 72 is pivotable around the joint 78 in aplane substantially parallel to the pinna 11.

In FIG. 3, the microphone module 70 is shown in the beamformer position,whereas in FIG. 4 it is shown in the T-Mic position. In the beamformerposition, the microphones 20A to 20E preferably are arranged in asubstantially horizontal plane, e.g. having a deviation of less than 20°from the horizontal direction. Preferably, the microphones 20A to 20Eare oriented “downwardly” in the beamformer position in order to providesome mechanical protection to the microphones 20A to 20E, such as fromrain, i.e. the microphones 20A to 20E are located at that side of thesupport element 72 which faces the floor in the beamformer position andthe microphone membranes are in a substantially horizontal plane (i.e.parallel to the floor). In the T-Mic position the microphones 20A to 20Epreferable are arranged in a substantially vertical plane, e.g. having adeviation of less than 30° from the vertical direction.

Preferably, only the microphone closest to the free end 76 of thesupport element 72, i.e. the microphone 20A, or only the two microphonesclosest to the free end 76, i.e. the microphones 20A and 20B, are activein the T-Mic mode in order to act as the T-Mic. Typically, the at leastone microphone 20A (or 20A and 20B) acting as the T-Mic is located atthe entrance 13 of the ear canal in the T-Mic position of the supportelement 72 (typically, the free end 76 of the support element 72 islocated close to the entrance 13 of the ear canal in the T-Mic position(see FIG. 4)).

According to a variant, the at least one microphone acting as the T-Micmay be oriented in an axial direction of the support element 72, asindicated by dashed lines at 20F, rather than being oriented in atransverse direction with regard to the support element 72 (as themicrophones 20A to 20E in FIG. 3). As can be seen in FIG. 3, such axialmicrophone 20F would be oriented “horizontally” in the beamformer mode,i.e. the microphone membrane would be in a substantially vertical plane.

Due to the essentially horizontal orientation of the microphones 20A to20E in FIG. 3, a directional characteristic/polar pattern can beachieved in a substantially horizontal plane by appropriate signalprocessing.

According to one embodiment, the microphone module 70 includes circuitry80 for combining the output signals of the microphones 20A to 20Eaccording to a beamforming algorithm in order to supply a beamformersignal to the sound processor unit 24 for use in the beamformer mode(this embodiment is indicated by dashed lines in FIG. 1). By providingsuch beamformer circuitry 80 in the microphone module 70, the soundprocessor unit 24 can be simplified, thereby requiring less complexcircuitry to be included in the BTE housing 27.

According to an alternative embodiment, the beamforming algorithm isfully implemented in the sound processor unit 24, with the audio signalof each microphone 20A to 20E being supplied separately to the soundprocessor unit 24, as indicated by the solid lines in FIG. 1 (in thiscase there is no beamformer signal processing in the microphone module70).

Preferably, the microphone module 70 is detachable from the BTE housing27 in order to enable replacement of the microphone module 70, forexample, in case of damage or degradation of one or several of themicrophones of the microphone module 70.

The support element 72 of the microphone module 70 may be moved from thesubstantially horizontal beamformer position shown in FIG. 3 to thesubstantially vertical T-Mic position shown in FIG. 4 and back to thebeamformer position by simple manual action by the patient.

According to one embodiment, the sound processor module 25 is adapted todetermine the position of the support element 72 in order toautomatically switch between the beamformer mode and the T-Mic modebased on the determined position of the support element 72. To this end,the microphone module 70 may comprise a sensor, for example aninclinometer/gravity sensor, in order to determine whether the supportelement 72 is in the beamformer position or in the T-Mic position.Typically, the beamformer mode is only used when the support element 72is in the beamformer position, whereas the T-Mic mode typically is usedonly when the support element 72 is in the T-Mic position. Thereby, thepatient may switch between the beamformer mode and the T-Mic mode andvice versa by simple manual action on the support element 72.

The sound processor module 25 may comprise a classifier unit (which maybe functionally implemented in the sound processor unit 24) fordetermining a presently prevailing auditory scene by analyzing the inputaudio signals, as it is known in the art (for example, the classifiermay determine that a single speaker in a noisy environment is speakingto the patient). The output of such classifier may be used, for example,to activate the beamformer mode once an auditory scene is detected inwhich beamforming is particularly helpful (for example, when theclassifier found that there is a single speaker in a noisy environment);typically, such activation will be enabled only in case that the supportelement 72 is found to be in the beamformer position, since a beamformermode would not be effective in the substantially vertical orientation ofthe support element 72 in the T-Mic position. Similarly, when thesupport element 72 is found to be in the T-Mic position, the T-Mic modemay be activated once an auditory scene has been detected in which theT-Mic mode is particularly helpful, such as the use of a telephonedevice; for example, it might be possible for the classier to select anoptimal microphone for a particular telephone instrument or handsetlocation.

Further, the sound processor unit 24 may automatically switch betweena—more or less—tight beamformer mode and an omnidirectional mode,depending on the output of the classifier, when the support element 72is in the beamformer position. In particular, an adaptive beamformingfunction may be implemented by using an adaptive beamforming algorithmin the beamformer mode which adapts the polar pattern of the beamformingaccording to the present auditory scene as determined by analyzing theinput audio signals. For example, the polar pattern of the beamformingmay be adapted to a noise field and/or a position of a target audiosource, such as a speaker, as determined from analyzing the input audiosignals. Such adaptive beamforming algorithm allows not only toimplement end-fire arrays (forward and backward oriented) but also broadside arrays and other configurations, depending on the “look direction”of the patient and the position of the target source (such as aspeaker).

In a bilateral system comprising a sound processor module at each of thepatient's ears, a bilateral/binaural beamformer may be implemented incase that there is a wireless link between the two sound processormodules; in such system, a contralateral input audio signal captured bya microphone assembly/module of the contralateral sound processor moduleis received by the ipsilateral sound processor module and is utilized ina binaural beamforming algorithm together with the ipsilateral inputaudio signals. Thereby, their activity may be increased, compared to amonolateral beamformer.

According to one embodiment, the sound processor module 25 may beadapted to monitor the performance of each of the microphones 20A to 20Eof the microphone module 70 by analyzing the respective input audiosignals in order to disable/mute microphones having a performance belowa given performance threshold.

It is to be understood that the invention may be used not only withauditory prostheses providing for neural stimulation only; rather, theinvention also may be used with additional acoustic stimulation of thepatient's residual hearing, namely bimodal systems (neural stimulationat one ear, acoustic stimulation at the other ear) and EAS systems(combined neural and acoustic stimulation at the same ear.

The invention claimed is:
 1. A behind-the-ear (BTE) sound processormodule for use in a device for neural stimulation of a patient'shearing, comprising: a BTE-housing to be worn behind an ear of thepatient; an adjustable microphone module attached to the BTE-housing forcapturing input audio signals from ambient sound; a sound processor unitfor generating, from the input audio signals, a neural hearingstimulation signal to be supplied to an implantable neural stimulationarrangement, wherein the microphone module comprises a plurality ofmicrophones and a support element for carrying the microphones, whereinthe support element is movable between a first position enabling theplurality of microphones to act as a directional microphone array in afirst audio signal processing mode of the sound processor unit and asecond position enabling at least one of the microphones to act, inaccordance with a second audio signal processing mode of the soundprocessor unit, as a microphone that is placed within a concha of an earof the patient at a position closer to the entrance of the ear canalthan in the first position.
 2. The sound processor module of claim 1,wherein the microphone module is designed as an earhook.
 3. The soundprocessor module of claim 1, wherein the microphone module is detachablefrom the BTE-housing in order to enable replacement of the microphonemodule.
 4. The sound processor module of claim 1, wherein the microphonemodule includes circuitry for combining the output signals of themicrophones according to a beamforming algorithm in order to supply abeamforming signal to the sound processor unit for use in the firstaudio signal processing mode.
 5. The sound processor module of claim 1,wherein the microphones are arranged as a linear array.
 6. The soundprocessor module of claim 1, wherein in the beamformer first position ofthe support element the microphones are arranged in a substantiallyhorizontal plane having a deviation of less than 20° from the horizontaldirection, when the sound processor module is worn by the patient. 7.The sound processor module of claim 1, wherein in the second position ofthe support element the microphones are arranged in a substantiallyvertical plane having a deviation of less than 30° from the verticaldirection, when the sound processor module is worn by the patient. 8.The sound processor module of claim 1, wherein the support element isdesigned as an arm having a free end and having another end connectedvia a joint to an upper end of the BTE-housing.
 9. The sound processormodule of claim 8, wherein the support element is pivotable around thejoint in plane substantially parallel to the pinna of the patient's ear,when the sound processor module is worn by the patient.
 10. The soundprocessor module of claim 8, wherein the at least one microphone actingas the microphone that is placed within the concha of the ear of thepatient is located at the free end of the support element.
 11. The soundprocessor module of claim 10, wherein the at least one microphone actingas the microphone that is placed within the concha of the ear of thepatient is oriented in an axial direction of the support element. 12.The sound processor module of claim 8, wherein in the second positionthe free end of the support element is located at the entrance of theear canal, when the sound processor module is worn by the patient. 13.The sound processor module of claim 8, wherein in the second audiosignal processing mode only the microphone closest to the free end ofthe support element is active or only the two microphones closest to thefree end of the support element are active.
 14. The sound processormodule of claim 1, wherein in the first position at least two of themicrophones are oriented downwardly, when the sound processor module isworn by the patient, said at least two microphones being located at aside of the support element which faces the floor in the first position.15. The sound processor module of claim 1, wherein in the first positionat least one of the microphones is oriented horizontally, when the soundprocessor module is worn by the patient, with a membrane of said atleast one of the microphones being in a vertical plane in the firstposition.
 16. The sound processor module of claim 1, wherein the soundprocessor module is adapted to determine the position of the supportelement and to automatically switch between the first audio signalprocessing mode and the second audio signal processing mode based on thedetermined position of the support element.
 17. The sound processormodule of claim 16, wherein the microphone module comprises a sensor fordetermining whether the support element is in the first position or inthe second position.
 18. The sound processor module of claim 1, whereinthe sound processor module comprises a classifier for determining apresent auditory scene by analyzing the input audio signals, and whereinthe sound processor unit is adapted to automatically select an audiosignal processing mode based on the determined auditory scene.
 19. Thesound processor module of claim 18, wherein in the first audio signalprocessing mode an adaptive beamforming algorithm is used which adaptsthe polar pattern of the beamforming according to the present auditoryscene determined by the classifier.
 20. The sound processor module ofclaim 19, wherein the polar pattern of the beamforming is adapted to anoise field and/or a position of a target audio source as determined bythe classifier.
 21. The sound processor module of claim 1, wherein thesound processor unit is adapted to automatically activate the firstaudio signal processing mode only when the support element is in thefirst position.
 22. The sound processor module of claim 21, wherein thesound processor unit is adapted to automatically switch between thefirst audio signal processing mode and an omnidirectional mode when thesupport element is in the first position.
 23. The sound processor moduleof claim 1, wherein the sound processor module is adapted to monitor theperformance of each of the microphones by analyzing the input audiosignals to disable microphones having a performance below a performancethreshold.
 24. The sound processor module of claim 1, wherein the soundprocessor module is adapted to receive, via a wireless link, acontralateral input audio signal captured by a microphone assembly of asound processor module to be worn at the other ear of the patient, andto utilize such contralateral input audio signal in a binauralbeamforming algorithm.
 25. The sound processor module of claim 1,wherein the microphone module is attached to the BTE-housing via anadaptor.
 26. A system for neural stimulation of a patient's hearing,comprising: a behind-the-ear (BTE) sound processor module for use in adevice for neural stimulation of a patient's hearing, comprising: aBTE-housing to be worn behind an ear of the patient; an adjustablemicrophone module attached to the BTE-housing for capturing input audiosignals from ambient sound; a sound processor unit for generating, fromthe input audio signals, a neural hearing stimulation signal to besupplied to an implantable neural stimulation arrangement, wherein themicrophone module comprises a plurality of microphones and a supportelement for carrying the microphones, wherein the support element ismovable between a first position enabling the plurality of microphonesto act as a directional microphone array in a first audio signalprocessing mode of the sound processor unit and a second positionenabling at least one of the microphones to act, in accordance with asecond audio signal processing mode of the sound processor unit, as amicrophone that is placed within a concha of an ear of the patient at aposition closer to the entrance of the ear canal than in the firstposition.
 27. The device of claim 26, wherein the neural stimulationarrangement is a cochlear implant stimulation arrangement comprising aplurality of electrodes for electrical stimulation of the cochlea.